SUSTAIN Pilot Study April 25, 2012 Curtis DeGasperi King County [email protected].

SUSTAIN Pilot Study

April 25, 2012Curtis DeGasperi

King [email protected]

System for Urban Stormwater Treatment and Analysis INtegrationSUSTAIN

Data Needs

• Land Use/Land Cover map in GIS• Watershed model

– Internal model in SUSTAIN– External model (Examples: HSPF, SWMM)

• BMP types, design configurations, costs• Instream targets

$0.0 $10.0 $20.0 $30.0 $40.0 $50.0 $60.0 $70.0 $80.0 $90.0

-10%

0%

10%

20%

30%

40%

50%

60%

All Solutions

Cost-Effectiveness Curve

Selected Solution

Cost ($ Million)

Effe

ctiv

en

ess

(%

Re

du

ctio

n)

Cost-Effectiveness Optimization

Cost in Millions of Dollars

Effec

tiven

ess

(%Re

ducti

on)

0

0.0

24

81

61

8

0.0

85

47

79

4

0.0

85

47

79

4

0.1

95

77

20

6

0.2

06

80

14

7

0.2

44

48

52

9

0.2

45

40

44

1

0.3

29

96

32

4

0.3

29

96

32

4

0.3

67

64

70

6

0.3

67

64

70

6

0.3

98

89

...

0.4

12

68

38

2

0.4

25

55

14

7

0.4

36

58

...

0.4

39

33

82

4

0.4

66

91

...

0.4

88

97

...

0.5

10

11

...

0.5

38

60

29

4

0.5

46

87

...

0.5

47

79

41

2

0.5

48

71

32

4

0.5

48

71

32

4

0.5

49

63

...

0.5

49

63

...

0.5

50

55

14

7

$0.0

$5.0

$10.0

$15.0

$20.0

$25.0POROUSPAVEMENTBIORETENTIONRAINBARRELWETPONDCISTERNSeries6

Effectiveness (% Reduction)

Co

st (

$ M

illio

n)

Cost-Effectiveness Optimization

Effectiveness (%Reduction)

Cost

in M

illio

ns o

f Dol

lars

30%

63%

7%

SUSTAIN BMP Modeling Assumptions

SUSTAIN Aggregate BMPs• On-site interception

– Rain barrel– Cistern– Green roof

• On-site treatment– Bioretention– Porous pavement– Infiltration trench

• Routing attenuation– Vegetative swale– Conduit

• Regional storage/treatment– Wet Pond– Dry Pond

Land Use-BMP TreatmentsNatural Drainage Design

Land Use-BMP TreatmentsNatural Drainage Design + Gray Infrastructure

50 gallon rain barrel$220 unit cost including construction$ 85.40 per yr I&E O&M assumed negligible

Total Present Value unit cost = $1,533

~3,000 gallon cistern$1,600 unit cost including construction$ 85.40 per yr I&E O&M assumed negligible

Total Present Value unit cost = $2,913

Residential On-site Detention Facilities

30-yr lifecycle cost assuming 5% discount rate

Bioretention Facilities

1 Unit is 100 ft2

$20/ft2 Design, permitting, and construction

Rain Garden$ 1.10/ft2-yr O&M$213.50 per yr I&ETPV cost = $69.73/ft2

Roadside Bioretention$ 1.10/ft2-yr O&M$170 per yr I&ETPV cost = $63.04/ft2 30-yr lifecycle cost assuming 5% discount rate

Porous Parking Areas

1 Unit is 100 ft2

$ 20/ft2 design, permitting, andconstruction$ 0.02/ft2 O&M$427.00 per yr I&E

TPV = $85.95/ft2

30-yr lifecycle cost assuming 5% discount rate

Detention Pond

1 Unit is ~13,000 ft3

$ 3.43/ft3 construction cost$ 1.20/ft3 design and permitting$ 0.01/ft3 O&M

TPV Cost = $ 25.81/ft2

or $ 4.78/ft3

Land cost = $18.25 ft230-yr lifecycle cost assuming 5% discount rate

Questions ?

SUSTAIN Pilot Catchment Study Results

Objectives

• Documentation– BMPs to be considered and associated treatment trains– BMP designs used in SUSTAIN– Cost assumptions used in model– Methods used to estimate road, rooftop and parking areas– Application of hydrologic target used in model– Extrapolation methods to biological and water quality

improvements• Describe general approach for expanding modeling

effort beyond pilot catchment

Pilot Catchment Scale Study

Green-Duwamish River Watershed Quality Assessmenthttp://www.kingcounty.gov/environment/watersheds/green-river/watershed-quality-assessment.aspx

Newaukum Urban Sub-basin

Pilot study area

Catchment NEW151

Newaukum Urban Sub-basin

Residential Rooftop and Commercial Parking Area Output

Building Height Model

Land Use/Land Cover

SUSTAIN Aquifers

Effective Impervious HRUs Pervious HRUs

Aggregate BMP

BMP Aquifer (Aquifer 1)

Pervious Aquifer(Aquifer 2)

AssessmentPoint

Surface Runoff

Pervious Subsurface FlowBMP Infiltration

BMP Outlet FlowRelease from BMP Aquifer

Release from Pervious Aquifer

Evaporation Loss

Optimization Decision VariablesHigh Pulse Count

Till Scenarios

Treatment TrainOn-site

Detention Pervious TreatmentAquifer Recession Coefficient (/hr)

Green Rain Barrel 0 0Green Rain Barrel 0 0.1Green Rain Barrel 80 0Green Rain Barrel 80 0.1Green Cistern 0 0Green Cistern 0 0.1Green Cistern 80 0Green Cistern 80 0.1

Green + Gray Rain Barrel 0 0Green + Gray Rain Barrel 0 0.1Green + Gray Rain Barrel 80 0Green + Gray Rain Barrel 80 0.1Green + Gray Cistern 0 0Green + Gray Cistern 0 0.1Green + Gray Cistern 80 0Green + Gray Cistern 80 0.1

Catchment NEW151 Very Poorly Drained Type D Soils

0%10%20%30%40%50%60%

%Effectiveness

0%10%20%30%40%50%60%

%Effectiveness

Rain Barrels Cisterns

EIA only +80% P EIA only +80% P EIA only +80% P EIA only +80% P

Rain Barrels Cisterns

$0.0

$5.0

$10.0

$15.0

$20.0

TPV Cost in $M

$0.00

$5.00

$10.00

$15.00

$20.00

TPV Cost in $M

Green + Gray on Till Scenarios

$0

$5

$10

$15

$20Detention Pond

Roadside Bioretention

Porous Parking

Rain Garden

Onsite Detention

BMP Cost BreakdownGreen+Gray Treatment Train on Till

Rain Barrels Cisterns

EIA only +80% P EIA only +80% P

$0

$5

$10

$15

$20

Private Capital

Public Capital

O&M

I&E

Green+Gray on Till Cost Breakdown

Rain Barrels Cisterns

EIA only +80% P EIA only +80% P

Cost-Effectiveness CurveGreen+Gray on Till Scenario 15

$0.0 $10.0 $20.0 $30.0 $40.0 $50.0 $60.0 $70.0 $80.0 $90.00

2

4

6

8

10

12

14

16

18

All Solutions

Cost-Effectiveness Curve

Selected Solution

Cost ($ Million)

Hig

h P

uls

e C

ou

nt

In terms of High Pulse Count

$0.0 $10.0 $20.0 $30.0 $40.0 $50.0 $60.0 $70.0 $80.0 $90.015%

20%

25%

30%

35%

40%

45%

50%

55%

All Solutions

Cost-Effectiveness Curve

Selected Solution

Cost ($ Million)

%M

axi

mu

m B

-IB

IIn terms of Log-Linear Regression Model

relating HPC to B-IBI

$0.0 $2.0 $4.0 $6.0 $8.0 $10.0 $12.0 $14.0 $16.0 $18.0 $20.015%

25%

35%

45%

55%

65%

75%

All SolutionsCost-Effectiveness CurveSelected Solution80% UCL80% LCL

Cost ($ Million)

%M

axi

mu

m B

-IB

IIn terms of %ofMaximum B-IBI including

uncertainty bounds (80% CL)

Water Quality Extrapolation

• SUSTAIN model includes TSS• Extrapolate to turbidity, Cu and Zn using 95%

Upper CL regression equations• Calculate TSS, Total Cu and Total Zn load

reductions• Calculate frequency of exceedance of

turbidity, Dissolved Cu and Dissolved Zn standards

Water Quality ExtrapolationSelected “Best” of Best Scenarios

• Up to ~80% reduction in TSS loads• Copper and Zinc loads reduced 30-40%• Frequency of exceedance of turbidity standard

reduced ~85%• Copper was not predicted to exceed standards

under current conditions• A low frequency of exceedance of the Zn

standard was effectively eliminated

Conclusions

• A variety of BMP treatment systems can meet similar targets at a variety of costs

• Generally, Green+Gray treatment trains performed better than Green only

• Effectiveness is highly dependent on assumptions regarding the fate of BMP infiltration

Recommendation

• Extend catchment modeling approach to a number of other catchments with relatively homogeneous land use/land cover

Questions ?

Approach to Scaling Up

Approach to Scaling Up

Questions ?